Please merge integration test

Philip,

Thank you for ruby_route_53!

These changes add an integration test that creates and deletes actual zones and records with AWS. It uses VCR to record AWS's responses, and uses the recorded responses on future runs. 68% of the lines are executed by the test.

I'd like to do more -- refactoring, unit testing and adding features -- but I'd first like to have this integration test in place to prevent regressions.

Thanks,

Aaron